This is one of the worst hotels i have ever stayed in.

The rooms on the subway tracks side have absolutely zero sound insulation.
Might as well just have the room on the railway tracks themselves.
Only from 1am to 6am, is there quiet.
Other than those times, the subway train sounds are simply really really loud.

No other room to move to as well.
On 2nd day, managed to get a room facing the street.
Able to hear street car sounds but a lot better than the constant subway noises.

Many other guests were trying to change rooms too...

The bed itself creaked and groaned loudly when moving on the bed.
We moved rooms and the 2nd room was the same.
The shower in this 2nd room was just not clean and brown stains were all over the white plaster.

Overall worst than a motel quality.
Guess there is a reason why this is Marriotts cheapest hotel in Korea.

Really do not recommend this hotel to anyone.